nixpkgs/pkgs/lib/default-unstable.nix
Marc Weber 8f3a8b5006 renamed chosenOptions to chooseOptionsByFlags and added support for optionals
(thus you don't need to write flag definitions, passing a dependency or not is enough)

svn path=/nixpkgs/trunk/; revision=9167
2007-08-19 17:24:05 +00:00

318 lines
13 KiB
Nix

# Utility functions.
let
inherit (builtins)
head tail isList stringLength substring lessThan sub listToAttrs;
in
rec {
# "Fold" a binary function `op' between successive elements of
# `list' with `nul' as the starting value, i.e., `fold op nul [x_1
# x_2 ... x_n] == op x_1 (op x_2 ... (op x_n nul))'. (This is
# Haskell's foldr).
fold = op: nul: list:
if list == []
then nul
else op (head list) (fold op nul (tail list));
# Concatenate a list of lists.
concatLists =
fold (x: y: x ++ y) [];
# Concatenate a list of strings.
concatStrings =
fold (x: y: x + y) "";
# Place an element between each element of a list, e.g.,
# `intersperse "," ["a" "b" "c"]' returns ["a" "," "b" "," "c"].
intersperse = separator: list:
if list == [] || tail list == []
then list
else [(head list) separator]
++ (intersperse separator (tail list));
concatStringsSep = separator: list:
concatStrings (intersperse separator list);
# Flatten the argument into a single list; that is, nested lists are
# spliced into the top-level lists. E.g., `flatten [1 [2 [3] 4] 5]
# == [1 2 3 4 5]' and `flatten 1 == [1]'.
flatten = x:
if isList x
then fold (x: y: (flatten x) ++ y) [] x
else [x];
# Return an attribute from nested attribute sets. For instance ["x"
# "y"] applied to some set e returns e.x.y, if it exists. The
# default value is returned otherwise.
# comment: I'd rename this to getAttrRec or something like that .. (has the same name as builtin.getAttr) - Marc Weber
getAttr = attrPath: default: e:
let {
attr = head attrPath;
body =
if attrPath == [] then e
else if builtins ? hasAttr && builtins.hasAttr attr e
then getAttr (tail attrPath) default (builtins.getAttr attr e)
else default;
};
# Filter a list using a predicate; that is, return a list containing
# every element from `list' for which `pred' returns true.
filter = pred: list:
fold (x: y: if pred x then [x] ++ y else y) [] list;
# Return true if `list' has an element `x':
elem = x: list: fold (a: bs: x == a || bs) false list;
# Find the sole element in the list matching the specified
# predicate, or returns the default value.
findSingle = pred: default: list:
let found = filter pred list;
in if found == [] then default
else if tail found != [] then
abort "Multiple elements match predicate in findSingle."
else head found;
# Return true if each element of a list is equal, false otherwise.
eqLists = xs: ys:
if xs == [] && ys == [] then true
else if xs == [] || ys == [] then false
else head xs == head ys && eqLists (tail xs) (tail ys);
# Determine whether a filename ends in the given suffix.
hasSuffix = ext: fileName:
let lenFileName = stringLength fileName;
lenExt = stringLength ext;
in !(lessThan lenFileName lenExt) &&
substring (sub lenFileName lenExt) lenFileName fileName == ext;
# Bring in a path as a source, filtering out all Subversion and CVS
# directories, as well as backup files (*~).
cleanSource =
let filter = name: type: let baseName = baseNameOf (toString name); in ! (
# Filter out Subversion and CVS directories.
(type == "directory" && (name == ".svn" || name == "CVS")) ||
# Filter out backup files.
(hasSuffix "~" name)
);
in src: builtins.filterSource filter src;
# Return a singleton list or an empty list, depending on a boolean
# value. Useful when building lists with optional elements
# (e.g. `++ optional (system == "i686-linux") flashplayer').
optional = cond: elem: if cond then [elem] else [];
# Return a list of integers from `first' up to and including `last'.
range = first: last:
if builtins.lessThan last first
then []
else [first] ++ range (builtins.add first 1) last;
# Return true only if there is an attribute and it is true.
checkFlag = attrSet: name:
if (name == "true") then true else
if (name == "false") then false else
if (isInList (getAttr ["flags"] [] attrSet) name) then true else
getAttr [name] false attrSet ;
logicalOR = x: y: x || y;
logicalAND = x: y: x && y;
# Input : attrSet, [ [name default] ... ], name
# Output : its value or default.
getValue = attrSet: argList: name:
( getAttr [name] (if checkFlag attrSet name then true else
if argList == [] then null else
let x = builtins.head argList; in
if (head x) == name then
(head (tail x))
else (getValue attrSet
(tail argList) name)) attrSet );
# Input : attrSet, [[name default] ...], [ [flagname reqs..] ... ]
# Output : are reqs satisfied? It's asserted.
checkReqs = attrSet : argList : condList :
(
fold logicalAND true
(map (x: let name = (head x) ; in
((checkFlag attrSet name) ->
(fold logicalAND true
(map (y: let val=(getValue attrSet argList y); in
(val!=null) && (val!=false))
(tail x))))) condList)) ;
isInList = list: x:
if (list == []) then false else
if (x == (head list)) then true else
isInList (tail list) x;
uniqList = {inputList, outputList ? []}:
if (inputList == []) then outputList else
let x=head inputList;
newOutputList = outputList ++
(if (isInList outputList x) then [] else [x]);
in uniqList {outputList=newOutputList;
inputList = (tail inputList);};
condConcat = name: list: checker:
if list == [] then name else
if checker (head list) then
condConcat
(name + (head (tail list)))
(tail (tail list))
checker
else condConcat
name (tail (tail list)) checker;
# calls a function (f attr value ) for each record item. returns a list
mapRecordFlatten = f : r : map (attr: f attr (__getAttr attr r) ) (__attrNames r);
# to be used with listToAttrs (_a_ttribute _v_alue)
av = attr : value : { inherit attr value; };
id = x : x;
# true if all/ at least one element(s) satisfy f
all = f : l : fold logicalAND true (map f l);
any = f : l : fold logicalOR false (map f l);
# iterates over a list of attributes collecting the attribute attr if it exists
catAttrs = attr : l : fold ( s : l : if (__hasAttr attr s) then [(__getAttr attr s)] ++ l else l) [] l;
flattenSet = set : map ( attr : __getAttr attr set) (__attrNames set);
mapIf = cond : f : fold ( x : l : if (cond x) then [(f x)] ++ l else l) [];
# Marc 2nd proposal: (not everything has been tested in detail yet..)
# One example showing how to use mandatory dependencies [1], default flags [2], ..
#
# note that you should be able to use either ["value1"] or just "value" .. (if I haven't forgotten a flatten)
# linuxthreads
#args: with args.lib; with args;
#let
# flagDescr = {
# defaults = { implies = [ "addOns" "addOns2"]; }; [> [2] defaults and mandatory should be the first listed ? Would you like it different?
# mandatory ={ cfgOption = [ "--with-headers=${args.kernelHeaders}/include" [> [1]
# "--with-tls" "--without-__thread" "--disable-sanity-checks" ];
# assertion = [ args.glibc.nptl ];
# };
# addOns = { cfgOption = "--enable-add-ons"; };
# addOns2 = { cfgOption = "--enable-add-ons2"; implies = "addOns"; };
# alternativeAddOn = { cfgOption = "--enable-add-ons-alt"; blocks = ["addOns", "addOns2"]; };
# justAOption = { };
# };
# co = chooseOptionsByFlags flagDescr ["libpng", "libjpg"] args;
#in args.stdenv.mkDerivation {
# # passing the flags in case a library using this want's to check them (*) ..
# inherit (co) /* flags */ buildInputs configureFlags;
# inherit (co.flags) justAOption;
# extraSrc = (if co.flags.justAOption then null else src = .. );
# src = fetchurl {
# url = http://ftp.gnu.org/gnu/glibc/glibc-2.5.tar.bz2;
# md5 = "1fb29764a6a650a4d5b409dda227ac9f";
# };
#}
# (*) does'nt work because nix is seeing this set as derivation and complains about missing outpath.. :-(
# using mkDerivation { ... } // oc.flags would work but would also force evaluation.. ( would be slower )
# resolves chosen flags based on flagDescr passed dependencies in args
# flagDescr : { name = { cfgOption = "..."; buildInputs = "..."; blocks = "..."; implies = "...";
# assert = "bool";
# any other options you need which you can get by catAttrs };
# ...
# args = { inherit lib stdenv;
# , inherit < all deps >;
# }
# flags = list of chosen options..
#
# returns: chosen ( like flagDescr but only containing the attributes elected by flags or by implies
# chosenFlat ( chosen flattened to list)
# buildInputs
# configureFlags (both to be passed to mkDerivation)
# flags = { flagName = true/ false for each attribute in flagDescr
# ... }
# optionals is a list of dependency names. If passed as attribute in args they'll be automatically added
# to flags and flagDescr ( optionalName = { buildInputs = optionalName } )
chooseOptionsByFlags = flagDescr : optionals : args :
let givenOptionals = listToAttrs
(mapIf ( a : (__hasAttr a args) )
( x: av x { buildInputs = x; } )
optionals );
fd = flagDescr // givenOptionals;
in chooseOptionsByFlags2 fd args ( getAttr ["flags"] [] args ++ (__attrNames givenOptionals ) );
chooseOptionsByFlags2 = flagDescr : args : flags :
let
# helper function
collectFlags = state : flags :
fold ( flag : s :
if (__hasAttr flag s.result) then s # this state has already been visited
else if (__hasAttr flag s.blockedFlagsBy) # flag blocked by priviously visited flags?
then throw "flag ${flag} is blocked by ${__getAttr flag s.blockedFlagsBy}"
else if (! __hasAttr flag flagDescr) then throw "unkown flag `${flag}' specified"
else let fDesc = (__getAttr flag flagDescr);
implied = flatten ( getAttr ["implies"] [] fDesc );
blocked = flatten ( getAttr ["blocks"] [] fDesc );
s2 = s //
{ blockedFlagsBy =
s.blockedFlagsBy
// listToAttrs ( map (b: av b flag)
blocked );
result = s.result
// (collectFlags s implied)
// listToAttrs [ { attr = flag; value = (__getAttr flag flagDescr); } ]; };
# add the whole flag to the result set
in assert (fold ( b : t : __trace (__attrNames s.result) (
if ( __hasAttr b s.result )
then throw "flag ${b} is blocked by ${flag}"
else if ( b == flag) then throw "flag ${b} blocks itself"
else t)) true blocked);
s2) state flags;
# chosen contains flagDescr but only having those attributes elected by flags (or by implies attributes of elected attributes)
chosen = (collectFlags { blockedFlagsBy = {}; result = {}; } (flags ++ ["mandatory"])).result;
chosenFlat = flattenSet chosen;
in assert ( all id ( mapRecordFlatten ( attr : r : if ( all id ( flatten (getAttr ["assertion"] [] r ) ) )
then true else throw "assertion failed flag ${attr}" )
chosen) );
{
# compared to flags flagsSet does also contain the implied flags.. This makes it easy to write assertions. ( assert args.
inherit chosen chosenFlat;
buildInputs = map ( attr: if (! __hasAttr attr args) then throw "argument ${attr} is missing!" else (__getAttr attr args) )
(flatten (catAttrs "buildInputs" chosenFlat));
#buildInputNames = catAttrs "name" buildInputs;
configureFlags = concatStrings (intersperse " " ( flatten ( catAttrs "cfgOption" chosenFlat) ))
+ (if (__hasAttr "profilingLibraries" chosen) then "" else " --disable-profiling");
flags = listToAttrs (map ( flag: av flag (__hasAttr flag chosen) ) (__attrNames flagDescr));
};
}